GUARD 3348375 - Caterpillar

The information supplied in this service letter may not be valid after the termination date of this program.Do not perform the work outlined in this Service Letter after the termination date without first contacting your Caterpillar product analyst.
TERMINATION DATE
29Feb2008
PROBLEM
An improperly machined transition radius may exist between the cylinder rod and the rod eye for the 167-7996 Tilt Cylinders (for 992G AZX Wheel Loaders) and the 193-4075, 193-4076 Lift Cylinders (for 994F 442 Wheel Loaders). This improper or "Stepped" transition could create a stress riser that could significantly shorten the expected life of these rods, and may result in premature failure as the rod could suddenly break at the transition if they are installed on a machine.
ACTION REQUIRED
Refer to the attached Rework Procedure for the instructions on inspecting and reworking (if needed) the cylinders.
SERVICE CLAIM ALLOWANCES
Submit one claim for inspecting and/or reworking the rods in the cylinder groups that are in dealer parts stock. A 0.5 hour will be allowed for the inspection of the rods in the cylinder group, and a maximum of 5.0 hours will be allowed for reworking the rods in the cylinder group. The parts needed for reworking the rods are also covered under this program. Refer to the parts needed listed in the Rework Procedure.
PARTS DISPOSITION
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.
Rework Procedure
For cylinder groups with date code between June, 2006 to May, 2007 in dealer stock, check transition area Image 1.1.1 between rod eye and rod for rod part number 167-7997 in cylinder group 167-7996; rod 193-4081 in cylinder group 193-4075; and rod 193-4080 in cylinder group 193-4076. If step exists in the transition area as shown in Image 1.1.2, rework the cylinder rod per the below directions. If the transition area is as shown on Image 1.1.3, the cylinder rod does not need to be reworked.
Image1.1.1
Image1.1.2
Image1.1.3
Rework Procedure for cylinder part number 167-7996.
Refer to Disassembly and Assembly Manual, SENR5893, for the disassembly and assembly instructions for the 992G Tilt Cylinders.
Using a 35 Degree Diamond Insert with a 0.8 mm Radius set the Machine Feed to 0.14 mm/rev (0.0055 inch/rev) and Speed to 200 surface meters/min (650 surface feet/min). Adjust the flat distance between the Rod Radius and Eye Radius to allow for a smooth "Lead-In" and "Run-Out" to the outside surface of the Eye forging.
Image1.2.1
Note A: Allowance to provide smooth "Lead-In" and "Run-Out"